Re: Having to sign an NDA
There are many things to weigh up when offering a certification...
They want to make it repeatable and fair, if there is too much variation you will have people complaining that they got a harder set of questions than others.
The shortness of the exam is also a concern for some, none of it is especially difficult but people often lose time and fail to gain enough marks who would have passed if given a bit more time / less pressure. This teaches you to cut corners to get it done in the time, something you shouldn't really be doing in the real world.
The old CHECK model had the examiners mirroring your screen and watching what you did while discussing your progress as you went along, this was in some ways better as it gave them a good feel for the skill level of the candidate and someone who had been briefed how to complete the specific challenges but lacked in general skills had a chance of being caught out. On the other hand, people would complain it's too subjective and down to the whims of the examiners on the day.